LIGO Document G1100719-v1

Tools for GEO-600 test mass repair suspension.

The GEO-600 detector employs a triple pendulum suspension with a quasi-monolithic lower stage to minimise suspension thermal noise. Fused silica fibres are used to suspend the test masses. During 2010 the detector has been upgraded to GEO-HF which will focus primarily on frequencies above 500 Hz. There is a small risk that during this upgrade a suspension fibre may be damaged. A robust procedure for repairing the suspensions therefore needs to be in place in order to minimise downtime of the detector. This procedure utilises fused silica fibres which will be fabricated at University of Glasgow with a CO2 pulling machine. Fibers will be transported to the GEO site in a sealed enclosure and welding will take place with a H2-O2 flame (identical to the original GEO suspension). To prepare for this work we suspended an aluminum full scale prototype. The fibers were welded to silica ears attached to the aluminum model of a GEO test mass. In the poster we present the procedure for suspension fabrication, focusing on details of the fibre transportation container and welding technology.